Auto-follow is often a problem for me when I box, even when it's two different computers on the same Internet connection. There's just enough lag to cause problems, especially with corners, stanchions, etc. I think it's pretty unavoidable unless you find a way to control both toons directly, which may not even be EULA-legal.
I just take my time in dungeons and other areas with a lot of angles, at least on the corners. This goes back forever. I can remember back in the days of Vex Thal raids, other raiders would ask to auto-follow me when they had to go afk to take a leak or whatever and despite my best intentions they'd get stuck on stanchions or, at worst, fall into a lava river! And that's with 2 entirely different Internet connections.
Auto-follow in EQ has lots of issues that have nothing to do with boxing. If your boxing rig has lag, it will make it worse, but if it doesn't have lag, auto-follow will still be pretty bad.
I have gotten pretty good at auto-follow with my 3 box crew. The main points: don't run full speed for long periods unless you're literally in a wide open, flat zone. Keep pausing every few seconds and letting the others catch up. And when in places with tight turns, make WIDE turns, to help the corners not interfere. Think of those signs on the back of semi-trailers: This vehicle makes wide right turns :)
Tatanka Wolfdancer, 106 Wood Elf Druid, 7 x 300+ Master Artisan, 7 maxed trophies :)
Anaceup Mysleeves, 105 Erudite Mage, 2 x 300 Master Artisan
Snookims Whinslow, 105 Erudite Enchanter, 2 x 300 Master Artisan
<Inisfree>, Tunare (Seventh Hammer!)
Tatankaa (95 Inquis)/Urkell (38 Conj)/ Seanthornton (24 Pally), <Inisfree> Freeport server (some other server now)